1. Field of the Invention
The invention relates to an optical sight.
2. Description of the Related Art
Referring to FIGS. 1 to 3, a conventional laser optical sight is shown to include an outer barrel unit 1, an objective lens unit 2, an ocular lens unit 3, a magnification unit 4 disposed in the outer barrel unit 1 and operable to adjust magnification, an aiming unit 5 disposed at a rear end of the magnification unit 4, and a display unit 6 disposed in the outer barrel unit 1. The magnification unit 4 includes an inner barrel 401. The aiming unit 5 includes an aiming plate 501, a washer 502 disposed between the aiming plate 501 and a rear end of the inner barrel 401, and a pair of screw fasteners 503. The aiming plate 501 has a reticle 504 for aiming, and is formed with a pair of elongate holes 505. The washer 502 has a pair of through holes 506. The screw fasteners 503 are extended through the elongate holes 505 and the through holes 506 to secure the aiming plate 501 and the washer 502 to the rear end of the inner barrel 401. The display unit 6 includes a display 601. for showing a range 606 (for instance, 100 yards, as shown in FIGS. 4(c) and 4(d)), a prism 602 disposed in the inner barrel 401 and in front of the aiming unit 5, a light-collecting lens set 603 disposed between the display 601 and the prism 602, three press bolts 604 coupled threadedly to the outer barrel unit 1, and a pair of pull bolts 605 extending through the outer barrel unit 1 and coupled threadedly to the light-collecting lens set 603. The range 606 is imaged through rearward projection via the light-collecting lens set 603 and the prism 502.
With further reference to FIGS. 4(a) to 4(d), the aforementioned laser optical sight undergoes a calibration procedure for aiming precision before being delivered from a factory:
Step 1: The magnification unit 4 and the aiming unit 5 are aligned against a target chart 7 (see FIG. 4(a)) before they are disposed in the outer barrel unit 1, and a washer 502 having an appropriate thickness is selected for adjusting the position of the aiming plate 501 along a Z-axis such that the target chart 7 and the reticle 504 can be imaged clearly at the same time.
Step 2: Under different magnification ratios, the position of the aiming plate 501 on an XY-plane relative to the inner barrel 401 is adjusted so that the centers of the reticle 504 and the target chart 7 coincide (see FIG. 4(b)), followed by securing the aiming plate 501 to the inner barrel 401.
Step 3: The magnification unit 4 and the aiming unit 5 are disposed in the outer barrel unit 1, and the range 606 is displayed on the display 601. At this time, the image of the range 606 may not conform to a predetermined specified position (for example, the image of the range 606 is shown in FIG. 4(c) to be inclinedly disposed).
Step 4: The press bolts 604 and the pull bolts 605 are operated so as to adjust the front-rear and left-right inclinations of the light-collecting lens set 603 so that the image of the range 606 is adjusted to the predetermined specified position, as shown in FIG. 4(d).
Since the reticle 504 and the display 601 of the aforementioned laser optical sight are separately disposed, two different calibration mechanisms and two different calibration operations (steps 2 and 4) are needed in order to dispose the reticle 504 and the image of the range 606 at their specified positions. Moreover, the display unit 6 includes numerous components that result in a longer assembly time.